Such mechanism are generally constituted by a rack associated with a worm screw or with a gear wheel. The worm screw or gear wheel is rotated and it has its thread or its teeth meshing with the notches in the rack which is thus driven in translation.
In general, such transmission components require relatively complex and accurate machining in order to obtain a correct fit between the thread or the teeth and the notches of the rack.
For relatively rudimentary mechanisms, such as those used in agricultural machinery, it is not necessary to achieve highly accurate transmission, and it therefore appears that such components are relatively expensive compared with the use to which they are put.
An object of the invention is to provide a transmission system for use in particular in relatively rudimentary mechanisms of the type used in agricultural machines and which are of reduced cost while being very robust.
In addition, by construction, the transmission system of the invention does not require its components to be made highly accurately because there is a degree of flexibility in the way the components co-operate, as explained below.
The system of the present invention is particularly simple, both in structure and in the way it is made.